Why does the system need to be pressurized and filled with liquid before introducing ammonia? (Aqueous solution full circulation method)

The most important aspect is that it can reduce the losses caused by the vaporization of liquid ammonia. 　　If the pressure is high after the system is pressurized, the vaporization of liquid ammonia can be reduced ； Even after pressurization at medium pressure, some ammonia gas will still vaporize due to the low pressure (definitely less than when there is no pressure applied). However, after the system is filled with liquid, even if ammonia vaporizes, it can be recovered through liquid-phase washing, which reduces environmental pollution caused by the release of gaseous ammonia and also minimizes ammonia loss.

Purpose of pressurization: 1. To maintain the pressure of liquid ammonia at the inlet of the ammonia pump, preventing the liquid ammonia from vaporizing due to low pressure during pressurization. 2 Increase the pressure in a loop to speed up the startup process. 3 Removing air from the medium-pressure system is beneficial for safe production. 4 It facilitates the removal of water accumulated in equipment and pipelines, preventing liquid slugging after ammonia introduction. As for the purpose of filling with liquid, it is as described on the second floor.

Purpose of system pressurization: 1. After the system is pressurized, the medium-pressure level can rise rapidly to the pressure before discharge from the urine tower, thereby increasing the net head of the liquid ammonia pump and the methamine pump and preventing the pumps from vaporizing. 2. After the system is pressurized, it enables the removal of water accumulated in the equipment and at the dead corners of the pipes in the ammonia system, thereby preventing liquid slugging after ammonia is introduced. 3. If nitrogen is used for pressurization, it can displace the air in the medium-pressure system, reducing the risk of ammonia exploding in the presence of air. Purpose of filling the system with liquid: 1. Before introducing ammonia, a certain liquid level must be established in the system’s equipment; this allows some gaseous ammonia to be absorbed during the ammonia circulation process, resulting in an ammonia solution of a specific concentration, thereby providing the necessary absorbent components for the feeding process. 2. It also serves as a liquid seal for some equipment and pipelines.

Everything said is very good and correct; let me add a few more words: the temperature of liquid ammonia and its saturated pressure are directly related to each other. To keep ammonia in a liquid state, it is necessary to maintain a certain pressure. For example, at 40 degrees, the pressure corresponding to liquid ammonia is 1.5 Mpa; at 1 atmosphere of pressure, the temperature of liquid ammonia is minus 33 degrees. At temperatures above the saturation pressure, ammonia vaporizes from its liquid state.

Purpose of pressurization: 1. To easily raise the medium pressure during the ammonia circulation in the system. 2. Ensure that after the system is fed, the No. 1 methane pump and the ammonia pump operate normally